Browse Prior Art Database

OS/2 Logical File System

IP.com Disclosure Number: IPCOM000108356D
Original Publication Date: 1992-May-01
Included in the Prior Art Database: 2005-Mar-22
Document File: 2 page(s) / 68K

Publishing Venue

IBM

Related People

Gittins, RS: AUTHOR [+3]

Abstract

The OS/2* Logical File System, also known as OS2LFS, came about as a result of an effort to port the Andrew File System (AFS) from UNIX** to OS/2. This was part of providing the Distributed Computing Environment (DCE) on OS/2. Virtual File Systems (VFS) such as AFS represent file objects with virtual nodes or vnodes. All file operations are performed on vnodes. In a UNIX system, a layer of code known as the Logical File System converts file-oriented system calls to vnode operations. The OS2LFS seeks to provide the same kind of layering. The obvious benefit to having the OS2LFS is in the reduction of the porting effort. The OS2LFS offers mechanisms for mounting/unmounting virtual file systems, as well as OS/2 logical drives.

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OS/2 Logical File System

       The OS/2* Logical File System, also known as OS2LFS, came
about as a result of an effort to port the Andrew File System (AFS)
from UNIX** to OS/2.  This was part of providing the Distributed
Computing Environment (DCE) on OS/2.  Virtual File Systems (VFS) such
as AFS represent file objects with virtual nodes or vnodes.  All file
operations are performed on vnodes.  In a UNIX system, a layer of
code known as the Logical File System converts file-oriented system
calls to vnode operations.  The OS2LFS seeks to provide the same kind
of layering.  The obvious benefit to having the OS2LFS is in the
reduction of the porting effort. The OS2LFS offers mechanisms for
mounting/unmounting virtual file systems, as well as OS/2 logical
drives.

      The OS2LFS is a dynamically linked program and consists of four
components:
      1) OS2LFS support code which contains all the functions needed
to support the Logical File System, such as initialization, memory
allocation, etc.
      2) The VFS code handles the attachment of virtual file systems
to the OS2LFS.  The VFS code provides the mechanism with which
virtual file systems are mounted and unmounted.  When mounted, the
file system is linked to the OS2LFS and structures for it are
initialized. The VFS operations exported by the VFS layer conform to
AIX* 3.1.
      3) The mapping code maps OS/2 file-oriented system calls to one
or more appropriate vnode operations. When a system call, su...